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| United States Patent |
6,040,477
|
|
Hichri
, et al.
|
March 21, 2000
|
Sulfodechlorinating aromatic compounds
Abstract
Disclosed is method of sulfodechlorinating an aromatic compound. A
composition is prepared of (1) an aromatic compound having the general
formula
##STR1##
Where R is CHO or COOH and n is 1 to 3, (2) an alkali metal or alkaline
earth metal sulfite or bisulfite in an amount stoichiometric to about 20
mole % in excess of stoichiometric, (3) water in an amount sufficient to
form a solution of the sulfite or bisulfite, and (4) sufficient base to
raise the pH of the composition to about 10 to about 14. The composition
is heated at about 150 to about 200.degree. C. No catalyst is present in
the composition.
| Inventors:
|
Hichri; Habib (Snyder, NY);
Lesins; Viesturs (Buffalo, NY);
Sommer; Christopher C. (North Tonawanda, NY)
|
| Assignee:
|
Occidental Chemical Corporation (Dallas, TX)
|
| Appl. No.:
|
205409 |
| Filed:
|
December 3, 1998 |
| Current U.S. Class: |
562/46; 562/56; 568/31 |
| Intern'l Class: |
C07C 309/32; C07F 011/00 |
| Field of Search: |
562/30,46,47,56,426
568/31
|
References Cited
U.S. Patent Documents
| 2407351 | Sep., 1946 | Stammbach | 260/507.
|
| 4710322 | Dec., 1987 | Metz | 562/46.
|
Primary Examiner: Geist; Gary
Assistant Examiner: Vollano; Jean F
Attorney, Agent or Firm: Brookes; Anne E., Fuerle; Richard D.
Claims
We claim:
1. A method of sulfodechlorinating an aromatic compound comprising
(A) preparing a composition of
(1) an aromatic compound having the general formula:
##STR3##
where R is CHO or COOH and n is 1 to 3; (2) a sulfur-containing compound
selected from the group consisting of alkali metal sulfites, alkali metal
bisulfites, alkaline earth metal sulfites, and alkaline earth metal
bisulfites, in an amount stoichiometric to about 20 mole % in excess of
stoichiometric;
(3) water in an amount sufficient to form a solution of said
sulfur-containing compound; and
(4) sufficient base to raise the pH of said solution to about 10 to about
14; and
(B) heating said composition at about 150 to about 200.degree. C. where no
catalyst is present in said composition.
2. A method according to claim 1 wherein said aromatic compound is
o-chlorobenzaldehyde.
3. A method according to claim 1 wherein said sulfur containing compound is
sodium sulfite or potassium sulfite.
4. A method according to claim 1 wherein said sulfur containing compound is
a bisulfite.
5. A method according to claim 1 wherein said base is sodium hydroxide.
6. A method according to claim 1 wherein said pH is raised to about 11.5 to
about 12.5.
7. A method according to claim 1 wherein the amount of said sulfur
containing compound is about 8 to about 12 mole % in excess of
stoichiometric.
8. A method according to claim 1 wherein R is CHO.
9. A method according to claim 1 wherein R is COOH.
10. A method according to claim 1 wherein n is 1.
11. A method of sulfodechlorinating an aromatic compound comprising
(A) preparing a composition of
(1) an aromatic compound having the general formula
##STR4##
where R is CHO or COOH and n is 1 or 2; (2) alkali metal sulfite or
bisulfite in an amount about 8 to about 12 mole % in excess of
stoichiometric;
(3) water in an amount sufficient to form a solution; and
(4) sufficient sodium hydroxide to raise the pH of said composition to
about 11.5 to about 12.5; and
(B) heating said composition at about 170 to about 190.degree. C., where no
catalyst is present in said composition.
12. A method according to claim 11 wherein n is 1.
13. A method according to claim 11 wherein R is CHO.
14. A method of making o-sulfonylbenzaldehyde comprising
(A) preparing a composition of
(1) o-chlorobenzaldehyde;
(2) sodium sulfite in an amount about 8 to 12 mole % in excess of
stoichiometric;
(3) water in an amount sufficient to dissolve said sodium sulfite; and
(4) sodium hydroxide in an amount sufficient to raise the pH of said
composition to between 11.5 and 12.5; and
(B) heating said composition under pressure at about 170 to about
190.degree. C., wherein no catalyst is present in said composition.
15. A method according to claim 1 wherein the cation in said base is the
same as the cation in said alkali metal or alkaline earth metal sulfite or
bisulfite.
16. A method according to claim 1 wherein said composition is heated in an
autoclave.
17. A method according to claim 1 wherein said heating is at about 170 to
about 190.degree. C.
18. A method according to claim 1 wherein said heating is for about 8 to
about 16 hours.
19. A method according to claim 1 including the additional last step of
recovering the product by crystallization, extraction, or a salting out
process.
20. A method according to claim 1 wherein said pH is 12.
Description
BACKGROUND OF THE INVENTION
This invention relates to a process for replacing one or more chlorine
atoms on an aromatic ring with sulfonyl groups. In particular, it relates
to the reaction of a ring chlorinated aromatic aldehyde or carboxylic acid
with a sulfite or a bisulfite in water at a high pH.
The sodium salt of ortho-sulfonylbenzaldehyde (OSBAL) is an important
chemical intermediate in the food, dye, and electroplating industries. In
DE88952, it is prepared by reacting orthochlorobenzaldehyde (OCBAL) with
sodium bisulfite in a neutral medium in an autoclave at 190 to 200.degree.
C. and 8 atmospheres pressure (810 kPa) for 8 hours. In DE 2502912, it is
prepared by reacting OCBAL with sodium sulfite in an autoclave in the
presence of a KI catalyst at 140 to 150.degree. C. and 7 atmospheres
pressure (709 kPa) for 3 hours. However, these processes do not produce
OSBAL at the desired yield and purity levels.
SUMMARY OF THE INVENTION
We have discovered a process for converting OCBAL into OSBAL that give
nearly 100% conversion and nearly 90% yield. In our process, no catalyst
is use, so contamination of the product with catalyst is avoided.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Aromatic compounds useful in the process of this invention are aldehydes
and carboxylic acids having the general formula:
##STR2##
where R is CHO or COOH and n is 1 to 3. Aldehydes are preferred as they
are more reactive. In the formula, n is preferably 1 as those compounds
are more commercially valuable. The preferred aromatic compound is OCBAL
because OSBAL is important commercially.
The aromatic compound is reacted with an alkali metal or alkaline earth
metal sulfite or bisulfite. Sodium and potassium sulfites and bisulfites
are preferred as they are more stable and sulfites are preferred to
bisulfites as they have a higher pH. The amount of alkali metal or
alkaline earth metal sulfite or bisulfite present should be about
stoichiometric up to about 20 mole % in excess of stoichiometric. The best
results are obtained using about 8 to about 12 mole % in excess of
stoichiometric.
Sufficient water is used to form a solution of the alkali metal or alkaline
earth metal sulfite or bisulfite and keep the reactants in solution during
the reaction. Excess water should be avoided as it increases process cost.
Sufficient base is used to raise the pH of the solution to about 10 to
about 14. At lower pH's the yield is lower and at higher pH's the reaction
mixture is too concentrated; the best results are obtained at a pH between
about 11.5 and about 12.5. The preferred bases are alkali metal
hydroxides, such as sodium hydroxide and potassium hydroxide, although
other bases, such as Na.sub.2 O, K.sub.2 O, or Ca(OH).sub.2 can also be
used. Preferably, the cation in the base should be identical with the
cation in the alkali metal or alkaline earth metal sulfite or bisulfite.
After a composition of the aromatic compound, the alkali metal or alkaline
earth metal sulfite or bisulfite, the water, and the base has been
prepared, it is placed in an autoclave and is heated to about 150 to about
200.degree. C. At lower temperatures the yield is poorer and higher
temperatures may result in the production of byproducts and will require
more expensive equipment to contain the higher pressures; a preferred
temperature range is about 170 to about 190.degree. C. The pressure will
depend upon the temperature and the volume of the autoclave and the
quantity of reactants. The reaction can take about 8 to about 16 hours and
is faster at higher temperatures. No catalyst is present during the
reaction and the product is therefore uncontaminated by a catalyst. The
product can be recovered from the reaction mixture by crystallization,
extraction, a salting out process, or by other means.
The following examples further illustrate this invention.
EXAMPLE 1
Reactions were performed in a 300 mL autoclave ("Monel" construction)
equipped with a self-inducing type agitator, thermocouple, a heating
mantle, temperature control, rupture disk, gas inlets and outlets, and a
pressure gauge. Into the autoclave was placed a composition consisting of
OCBAL, 1.2 equivalents of sodium sulfite, 80 mL of water, 0.0003 moles of
catalyst (if used), and sufficient solid sodium hydroxide to reach the
desired pH. The autoclave was heated to 190.degree. C. for 6 hours. The
following table gives the conditions and results:
______________________________________
pH Catalyst Fractional Conversion
Fractional Yield
______________________________________
10 KI 0.99 0.60
12 none 0.97 0.72
10 none 0.84 0.81
12 KI 0.89
0.68
______________________________________
The table shows that the catalyst was of little benefit and actually
lowered the yield of OSBAL.
EXAMPLE 2
The following compositions were prepared:
______________________________________
Composition
Na.sub.2 SO.sub.3 (g)
OCBAL (g) H.sub.2 O (g)
______________________________________
1 19.7 20 160.3
2 26.9
20
153.1
3 33.3
33.7
133.0
4 34.8
25.9
139.3
______________________________________
The compositions were placed in the autoclave under the conditions given in
the following table:
______________________________________
Composition
Time (hrs)
T (.degree. C.)
pH Percent Yield
______________________________________
1 8 150 10 51
1 16
170
78
2 150
62
2 16
170
75
3 170
71
3 16
150
71
4 170
62
4 16
150
58
______________________________________
The table shows that reaction conditions of 170.degree. C., corresponding
to pressure of 115 psig (0.8 MPa), a pH of 12, and reaction time of 16
hours gave the highest yield.
EXAMPLE 3
The compositions of Example 2 were placed in the autoclave. The following
table gives the reaction conditions and the results:
______________________________________
T (C. .degree.)
Time (hrs)
pH Composition
Fractional Yield
______________________________________
190 16 12 1 0.78
190 16 12
0.82
190 16 12
0.88
190 16 12
0.82
______________________________________
The table shows that composition 3 had the highest yield.
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